The general background relating to coiled tubing injector units is described in U.S. Pat. Nos. 5,83 9,514 and 4,673,035 to Gipson which are incorporated herein by reference for all purposes.
Apparatus for conventional drilling with sectional tubing is very well known.
Coiled tubing has been a useful apparatus in oil field operations due to the speed at which a tool can be run in (injected) and tripped out (withdrawn) from a well bore. Coiled tubing is supplied on a spool. An injector at the wellhead is used to grip and control the tubing for controlled injection and withdrawal at the well. As coil tubing cannot be rotated, drilling with coiled tubing is accomplished with downhole motors driven by fluid pumped downhole from the surface.